1. Field of the Invention
The invention relates generally to efficient means for the generation of electrical or other power utilizing energy from subterranean geothermal sources and, more particularly, relates to novel arrangements including efficient deep well heat exchange and pumping equipment for application in deep hot brine wells for the transfer of thermal energy for use at the earth's surface.
2. Description of the Prior Art
A basic advance in the geothermal power extraction art, not limited to use with the rare dry steam geothermal sources and also devoid of the steam and geothermal brine separation problems and the consequent corrosion problems attached to prior art systems using mixed steam and hot water supply wells, was presented in the H. B. Matthews U.S. Pat. No. 3,824,793, issued Oct. 24, 1972 for a "Geothermal System and Method", and in the divisional application which resulted in the U.S. Pat. No. 3,898,020 of the same title, issued May 8, 1974. These Matthews patents provide an arrangement which will be discussed in further detail hereinafter in connection with FIGS. 1, 3a, and 3b.
Improvements in the basic Matthews concept appear in more recently filed U.S. patents also assigned to Sperry Rand Corporation:
K. e. nichols et al U.S. Pat. No. 3,905,196, issued Sept. 16, 1975 for a "Geothermal Energy Pump Thrust Balance Apparatus", PA1 J. l. lobach U.S. Pat. No. 3,908,380, issued Sept. 30, 1975 for a "Geothermal Energy Turbine and Well System", and PA1 H. b. matthews et al U.S. Pat. No. 3,910,050, issued Oct. 7, 1975 for a "Geothermal Energy System and Control Apparatus". The five aforementioned patents disclose geothermal energy recovery systems making use of thermal energy stored by subterranean heat sources in hot, solute-bearing well water to generate super-heated steam from a surface-injected flow of clean water; the super-heated steam is then used to operate a turbine-driven pump within the well for pumping the hot brine at high pressure and always in liquid state to the earth's surface, where it transfers its heat in a binary closedloop heat exchanger-vapor turbine-alternator combination for generation of electrical power. Residual brine is pumped back into the earth, while the clean, cooled water is regenerated at the surface-located system and is returned to the deep well pumping system for generating steam and also for lubrication of fluid bearings supporting the turbine-driven pump system. The latter three patents concern a similar system, illustrating improvement features in the form of hydro-dynamic radial and thrust bearings and pressurized liquid bearing lubrication means. A reverse flow deep well steam turbine motor of compact nature is also disclosed, along with features of the surface control and power generation systems.